Paper trimmer

ABSTRACT

A machine for trimming the backing sheet of a composite product having an open network fabric secured to a backing sheet includes a support for holding the product, and a movable separator bar having laterally spaced apart fingers for separating the sheet from the fabric along one edge of the product. A carriage moves a cutter bar between a cutting position adjacent the separated portion of the sheet and a clear position. The carriage also includes a blade which is movable relative to the cutter bar. The sheet is disposed between the blade and the cutter bar when the bar is in the cutting position, and the blade is actuated to cut the sheet once the bar is in the cutting position.

Rose

[11 3,802,047 [451 Apr. 9, 1974 PAPER TRIMMER Russell 0. Rose, Monterey Park, Calif.

Assignee: Davis Walker Corporation, Los

Angeles, Calif.

Filed: Feb. 5, 1973 Appl. No.: 329,331

Inventor:

US. Cl 29/200D, 83/558, 83/925 R Int. Cl B23p 19/00 Field of Search 29/200 D; 83/925 R, 557,

References Cited UNITED STATES PATENTS Primary Examiner-Willie G. Abercrombie Attorney, Agent, or Firm-Christie, Parker & Hale [5 7] ABSTRACT A machine for trimming the backing sheet of a composite product having an open network fabric secured to a backing sheet includes a support for holding the product, and a movable separator bar having laterally spaced apart fingers for separating the sheet from the fabric along one edge of the product. A carriage moves a cutter bar between a cutting position adjacent the separated portion of the sheet and a clear position. The carriage also includes a blade which is movable relative to the cutter bar. The sheet is disposed between the blade and the cutter bar when the bar is in the cutting position, and the blade is actuated to cut the sheet once the bat is in the cutting position.

11 Claims, 4 Drawing Figures PAPER TRIMMER BACKGROUND OF THE INVENTION This invention relates to material trimming apparatus, and more particularly to a machine for trimming a sheet of material which is secured to an open mesh fabrrc.

In the construction of plaster or stucco walls, the practice for many years has been to fasten several vertically spaced apart horizontal wires, called belly band wires, to the studs of the building wall frame, and thereafter nail a water-impermeable sheet, such as asphalt or tar paper, over the belly band wires. Lathing, such as wire mesh netting,is nailed to the studs over the tar paper, and stucco'or plaster is then applied to'the netting and paper. The construction of walls in this manner is a slow process because of the separate nailing operations required for the belly band wires, tar paper, and wire mesh netting.

This slow process has been avoided in recent years by a composite lath product which may be applied in a single nailing operation. In a typical composite lath, wire mesh netting is secured to a paper backing sheet, preferably conventional dry Kraft paper. The wire mesh netting overlies one side of the backing sheet, and elongated securing wires commonly are used on the other side of the backing sheet to fasten the wire mesh netting to the sheet. A second backing sheet, preferably tar paper, is secured to the other backing sheet, preferably by adhesive such as glue, to sandwich the securing wires between the backing sheets and leave the wire mesh netting exposed.

The composite lath is secured to studs, ceiling joists, and the like so that the wire mesh netting is exposed. Plaster or stucco is then applied to the netting to permeate the lath and form a lock with the wire mesh. The paper sheets help hold the stucco or plaster in place and provide a moisture barrier.

Composite lath generally is manufactured in long panels. The panels are nailed next to each other in rows around the building wall frame to cover the framework before the stucco or plaster is applied. Building codes require the wire mesh netting of contiguous lath panels to be interconnected to provide the equivalent of a continuous layer of wire mesh netting around the building framework.

Generally speaking, the outer edges of composite lath sheeting are cut in the factory by a single shearing step on which the edges of the wire mesh netting are aligned with the edges of the backing sheet. This presents problems when the lath sheeting is being nailed, because the backing sheets of contiguous lath panels interfere with the workmans ability to overlap and interconnect the wire mesh netting of the contiguous panels. Accordingly, workmen generally trim off an edge of the backing sheet of each panel by hand so the wire mesh netting overlaps the backing sheet, which facilitates interconnecting the wire mesh netting of adjoining lath panels prior to nailing. This trimming step istime consuming, and unnecessarily wastes valuable construction time. Moreover, the trimming step is generally difficult to do by hand, because the backing sheets of many composite lath panels include securing wires which are difficult to cut.

SUMMARY OF THE INVENTION This invention provides a machine capable of trimming the backing sheet of a composite lath panel so the wire mesh netting secured to the backing sheet will overlap the sheet. Thus, the composite lath panel produced by the machine can be put into use directly without the necessity of hand-trimming it.

Briefly, the machine includes means for holding a composite product having a sheet of material secured to an open network fabric, and means for separating the sheet from the fabric along an edge of the product. A shear disposed adjacent the separated edge of the product is moved relative to the product between a cutting position and a clear position. The shear includes a cutter bar and a blade movable relative to each other. The sheet is held between the blade and cutter bar when the shear is in its cutting position, and the shear is actuated to cut the paper when the shear is in the cutting position.

In a preferred form of the invention, the sheet is separated from the fabric by movable fingers for holding the sheet so it diverges from the fabric, and a carriage for moving the shear into its cutting position as the fingers hold the sheet in its separated position. The blade and bar move relative to each other along a fixed path inclined upwardly and away from the edge of the product to be trimmed. The inclined orientation of the cutter bar and blade allows the trimmed portion of the sheet to fall free from the machine after being sheared from the product. Preferably, the cutter bar is beveled to deflect the fabric away from the cutting position, and the blade is beveled to aid in deflecting the trimmed portion of the sheet from the cutting position.

BRIEF DESCRIPTION OF DRAWINGS These and other aspects of the invention will be more fully understood by referring to the following detailed description and the accompanying drawings in which:

FIG. 1 is a fragmentary elevation view, partly broken away, showing a trimming machine in accordance with this invention;

FIG. 2 is a fragmentary cross-sectional elevation view taken on line 2-2 of FIG. 1;

FIG. 3 is a plan view showing a typical composite lath product to be trimmed by the machine provided by this invention; and

FIG. 4 is'an electrical schematic diagram of the'control system for the trimming machine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and2 show a trimming machine which includes a horizontally disposed work support table 12 for holding work 14 in sheetform to be fed to the machine. The purpose of the machine is to trim a sheet of material which is secured to an open network fabric to form a composite product.

FIG. 3 shows a typical composite lath product 16 which can be trimmed by trimming machine 10. Composite lath 16 includes a conventional hexagonal wire mesh netting l8 overlying a backing sheet 19 which includes a sheet 20 of conventional dry Kraft paper. Laterally spaced apart, elongatedline wires 22 extending in the same general direction as the mesh wires and twistpoints of the wire mesh netting are on the opposite side of paper backing sheet 20. The line wires project through holes 24 formed in paper sheet 20, and are intertwisted with the twistpoints of the wire mesh netting with which they are aligned. A second backing sheet 26, preferably tar paper, is secured to the opposite side of paper backing sheet to sandwich the line wires between the backing sheet and leave the wire mesh netting exposed.

The remaining description of trimming machine 10 will be in the context of its use in trimming a composite lath panel, such as panel 16.

Long panels of composite lath lying on work table 12 are fed into the machine (in the direction of arrow 28 in FIG. 2) until the edge of to be trimmed strikes a downwardly depending leg of an L-shaped transverse stop bar 30. As the panel is being held against stop bar 30, backing sheet 19 is trimmed as follows. A pivotally mounted transverse separator bar 32 moves down from an initial raised position (shown in phantom line in FIG. 2) to a position where it separates backing sheet 19 from its overlying wire mesh netting 18. The separator bar pivots by a pair of elongated pivot arms 34 rigidly connected. to the opposite ends of the separator bar. The ends of pivot arms 34 remote from separator bar 32 are carried on the opposite ends of an elongated transverse separator bar rotation arm 36 mounted in bearing blocks (represented schematically at 38) carried by an upright frame 40 on opposite sides of the machine. Rotation arm 36 is rotated about its axis by a downwardly extending lever arm 41 rigidly secured to rotation arm 36. The remote end of lever arm 41 is coupled to a longitudinally slideable piston arm 42 of an air cylinder AC-l.

When the lath panel is initially inserted into the machine, separator bar 32 is in its initially raised position (shown in phantom line in FIG. 2) so each panel can be pushed into contact with stop bar 30. The trimming cycle of the machine is then initiated by actuating air cylinder AC-l to retract piston arm 42 to the position shown in FIG. 2. This causes lever arm 40 to rotate through a distance 1 to rotate arm 36 in a counterclockwise direction (as in FIG. 2), and thereby rotate separator arm 32 downwardly to its position shown in solid lines in FIG. 2. Separator arm 32 carries a series of laterally spaced apart L-shaped members having downwardly projecting fingers 46 which project through the open areas in wire mesh netting 18 to push against backing sheet 19 so it diverges away from the plane of the wire mesh netting.

While the separator bar and fingers are holding the backing sheet in its downwardly inclined, separated position shown in FIG. 2, a longitudinally movable carriage 48 is moved from an initial clear position (shown in phantom line in FIG. 2) to a cutting position shown in solid lines in FIG. 2. Carriage 48 includes a pair of upwardly inclined frame members 49 located on opposite sides of the machine and spaced inwardly from the inside walls of frame 40. Frame members 49 are rigidly held in place by an elongated transverse tie bar 50 rigidly secured at its ends to flanges 51 of frame members 49. An elongated transverse support bar 52 held in an inclined position between frame members 49 supports an elongated transverse cutter bar 54 which projects upwardly in an inclined plane toward the plane of work table 12.

Carriage 48 is supported by rollers 56 carried on mounting brackets 58 rigidly secured to the opposite outer edges of frame members 49. The rollers ride longitudinally back and forth in a track formed by. a pair of longitudinally extending and vertically spaced apart parallel rails 60 secured to the inner wall surface of each frame 40.

Carriage 48 also includes an elongated transverse support bar 62 extending between frame members 49 and lying in an inclined plane parallel to bar 52. A removable cutting blade 64 releasably secured to support bar 62 projects upwardly away from bar 62 toward cutting bar 54. The bottom of support bar 62 is coupled to a pair of laterally spaced apart slidable piston arms 66 of air cylinders AC3 extending upwardly in an inclined plane collinear with support bar 62. The bottom of each air cylinder AC3 is rigidly secured to an elongated transverse bar 70 rigidly held in place between frame members 49. One of the piston arms 66 is shown in FIG. 2 in its retracted position.

In use, piston arms 66 are extended in unison to move cutting blade 64 upwardly (in the direction of arrow 72 in FIG. 2). Support bar 62 and blade 64 ride in a guide channel formed by a pair of upwardly inclined guide bars 74 secured to the opposite inner wall surfaces of frame members 49.

After the backing sheet is separated from netting l8, carriage 48 is moved from its initial clear position (shown in phantom line in FIG. 2) to the cutting position (shown in solid lines in FIG. 2) by a linkage which includes a pair of laterally spaced apart, longitudinally extending link arms 76 secured to opposite ends of the carriage. A pair of lever arms 78 are pivotally secured to the opposite ends of link arms 76. The lever arms extend downwardly for connection to an elongated transverse rotation arm 80 mounted at its end in bearings (not shown) on opposite sides of frame 40. A downwardly depending lug 82 is rigidly attached to an intermediate portion of rotation arm 80 to rotate with arm 80. Lug 82 is pivotally secured to a longitudinally slidable piston arm 84 of an air cylinder AC-2.

In use, carriage 48 is moved into its cutting position by retracting piston arm 84 to move it through a distance 1 to rotate arm 80 about its axis. This pushes link arms 76 forward to push the carriage so that cutter bar 54 slides over the top of the downwardly deflected backing sheet 19, as shown in FIG. 2.

Once the cutter bar has reached the cutting position shown in FIG. 2, air cylinders AC3 are pressurized to extend piston arms 66 upwardly to move blade 64 into engagement with backing sheet 19 and past cutter bar 54 to shear off the backing sheet across its width. The blade is then immediately retracted by retracting piston arms 66.

The inclined orientation of carriage 48, blade 64, and bar 62 enables the trimmed portion of backing sheet 19 to fall under gravity in a pile below the machine. The leading edge of blade 64 is beveled, which aids in deflecting the trimmed portion of the backing sheet from the major portion of the sheet. The leading edge of cutter bar 54 also is beveled, which aids in deflecting the wire mesh fabric away from backing sheet 19 as the carriage is moved forwardly into contact with the sheet. Blade 64 trims backing sheets whether or not the backing sheet is reinforced with wire such as line wires 22.

After piston arm 66 has been retracted to the position shown in FIG. 2, air cylinder AC2 is then actuated to extend piston arm 84 through the distance I, which rotates arm 80 in a clockwise direction (as shown in FIG. 2) to pull carriage 48 back to its clear position.

The system for controlling the operating cycle of the machine is understood best by referring to FIG. 4. After the work is in place against the stop bar 30, the

' operator closes a normally open switch 88 to initiate After the delay provided by relay TDR-A, contact 98 closes to energize acoil 100 of a control 'relay 2-CR, which closes a normally open contact 102 of relay 2-CR to supply power to a valve coil 104 of air cylinder.

AC-2. This retracts piston am 84 to push carriage 48 into its cutting position. The closing of contact 102 also energizes a coil 106 of a time delay relay TDR-B, which closes a normally open contact 108 after a sufficient time delay to allow carriage 48 to reach its cutting position.

After the carriage has reached the cutting position,

. contact 108 closes to supply power to valve coils 1l0 of air cylinders AC-3, which extends piston arms 46 to push blade 64 upwardly to shear off the end of backing sheet 19. The closing of contact 108 also energizes a coil 112 of a time delay relay TDRC to close a normally open contact 114 after a sufficient time delay to allow the trimmed portion of the backing sheet to separate from the remaining portion of the backing sheet. After contact 114 is closed, power is supplied to valve coils 116 of air cylinders AC3 to retract piston arms 166 to move cutting blade 64 down to its inoperative position.

The closing of contact 114 also energizes a coil 118 of a time delay relay TDR-D to close a normally open contact 120 thereof, preferably after a short time delay which allows the piston arms 66 time to reach their retracted positions. Thereafter, contact 120 closes to supply power to valve coil 122 of air cylinder AC-2 to extend piston arm 84 and thereby move carriage 48 back to its clear position.

The closing of switch 120 also energizes a coil 124 of a time delay relay TDR-E, which closes a normally open contact 126 thereof after a short time delay which allows the carriage to return to its clear position. After the carriage has returned, contact 126 closes to energize a valve coil 128 of air cylinder AC-l to extend piston arm 42 and thereby rotate separator bar 32 to its raised position.

The closing of contact 126 also supplies power to a coil 130 of a time delay relay TDR-F to close a normally open contact 132 thereof after a sufficient time delay which enables the separator bar to reach its raised position. When contact 132 closes, it supplies power to a .coil 134 of a control relay 3-CR which opens a normally closed contact 136 of relay 3-CR to cut off power from the power supply and thereby move all relay contacts to their initial position in preparation for the next trimming cycle.

I claim:

1. Apparatus for trimming a sheet of material which is secured to an open network fabric to form a composite product, the apparatus comprising means for holding the product, means for separating the sheet from the fabric along one edge of the product, a shear disposed adjacent said one edge of the product, means for moving the shear relative to the product between a cutting position and a clear position, the shear having a cutter bar and a blade movable relative to each other, the sheet being between the blade and bar when the shear is in the cutting position, and means for actuating the shear to cut the sheet when the shear is in the cutting position. i

2. Apparatus according to claim 1 in which the separating means includes spaced apart fingers for holding the sheet so it diverges from the fabric away from said one edge. y

3. Apparatus according to claim 2 in which the fingers are mounted on an elongated carrier bar which pivots toward and away from the plane of the productholding means.

4. Apparatus according to claim 1 in which the cutter bar is beveled to deflect the fabric when the sheet is i being separated from the fabric.

5. Apparatus according to claim 1 in which the blade is beveled to deflect the sheet away from the point where the sheet is cut.

6. Apparatus according to claim 1 in which the blade and bar are movable relative to each other along a path inclined upwardly and away from said one edge of the product.

7. Apparatus according to claim 1 in which the pro duct-holding means comprises a table for holding the product adjacent the separating means.

8. Apparatus accordingto claim 7 in which the holding means further includes a stop for maintaining the product in a fixed position adjacent the separating means.

9. Apparatus according to claim 1 including a carriage for mounting the shear, and means for moving the carriage to move the shear between the cutting position and the clear position.

10. Apparatus according to claim 9 including first actuating means for moving the separating means to a position where it separates the sheet from the fabric, second actuating means operative in timed relation to the first actuating means for moving the carriage to the cutting position, and third actuating means operative in timed relation to the second actuating means for actufrom its fabric-separating position. a 

1. Apparatus for trimming a sheet of material which is secured to an open network fabric to form a composite product, the apparatus comprising means for holding the product, means for separating the sheet from the fabric along one edge of the product, a shear disposed adjacent said one edge of the product, means for moving the shear relative to the product between a cutting position and a clear position, the shear having a cutter bar and a blade movable relative to each other, the sheet being between the blade and bar when the shear is in the cutting position, and means for actuating the shear to cut the sheet when the shear is in the cutting position.
 2. Apparatus according to claim 1 in which the separating means includes spaced apart fingers for holding the sheet so it diverges from the fabric away from said one edge.
 3. Apparatus according to claim 2 in which the fingers are mounted on an elongated carrier bar which pivots toward and away from the plane of the product-holding means.
 4. Apparatus according to claim 1 in which the cutter bar is beveled to deflect the fabric when the sheet is being separated from the fabric.
 5. Apparatus according to claim 1 in which the blade is beveled to deflect the sheet away from the point where the sheet is cut.
 6. Apparatus according to claim 1 in which the blade and bar are movable relative to each other along a path inclined upwardly and away from said one edge of the product.
 7. Apparatus according to claim 1 in which the product-holding means comprises a table for holding the product adjacent the separating means.
 8. Apparatus according to claim 7 in which the holding means further includes a stop for maintaining the product in a fixed position adjacent the separating means.
 9. Apparatus according to claim 1 including a carriage for mounting the shear, and means for moving the carriage to move the shear between the cutting position and the clear position.
 10. Apparatus according to claim 9 including first actuating means for moving the separating means to a position where it separates the sheet from the fabric, second actuating means operatIve in timed relation to the first actuating means for moving the carriage to the cutting position, and third actuating means operative in timed relation to the second actuating means for actuating the shear to cut the sheet when the shear is in the cutting position.
 11. Apparatus according to claim 10 including fourth actuating means to deactivate the shear after the sheet is cut, fifth actuating means operative in timed relation to the fourth actuating means for moving the carriage to its clear position, and sixth actuating means operative in timed relation to the fifth actuating means for deactivating the separating means and retracting it from its fabric-separating position. 